btrfs-util: introduce btrfs_is_filesystem() and make use of it where appropriate

Let's unify the code that checks whether an fd is on btrfs a bit.

(Also, rename btrfs_is_snapshot() to btrfs_is_subvol(), since that's
usually how this is referred to in our code)

1 files changed, 2 insertions, 1 deletions

diff --git a/src/shared/btrfs-util.h b/src/shared/btrfs-util.h
index 02e46e30ea..a7eb895c93 100644
--- a/src/shared/btrfs-util.h
+++ b/src/shared/btrfs-util.h
@@ -49,7 +49,8 @@ typedef enum BtrfsSnapshotFlags {
         BTRFS_SNAPSHOT_RECURSIVE = 4,
 } BtrfsSnapshotFlags;
 
-int btrfs_is_snapshot(int fd);
+int btrfs_is_filesystem(int fd);
+int btrfs_is_subvol(int fd);
 
 int btrfs_subvol_make(const char *path);
 int btrfs_subvol_make_label(const char *path);